Which type of forest has the most porcini?

There is no single answer, because every type has its own bolete: in conifers the pine bolete, in broadleaf woods the oak cep, on birch edges the birch porcini. The most varied basket comes from mixed forest, where these trees stand side by side.

Are the porcini under pine and under birch the same mushroom?

No. The birch porcini is a form of the same species, Boletus edulis, while the pine bolete (Boletus pinophilus) is a recognised separate species. So under birch and spruce you have two forms of one mushroom, and under pine a different one.

What soil does porcini like?

Acidic, well-drained, sandy. In productive oak stands soil acidity was measured at pH 4.6. The bolete avoids limestone soils, and there you meet the brightly coloured boletes instead.

Why do bay boletes grow in an old pine forest instead of porcini?

Because porcini chooses stands of middle age, and in older conifer stands it yields its place to the bay bolete. This is described in the section on the ecology of porcini in the Polish Wikipedia. In a tall old pine forest, set your expectations on the bay bolete.

Which plants hint that porcini may be here?

In a pine forest it is wavy hair-grass (Avenella flexuosa), a fine grass, and lichens of the genus Cladonia. They like the same acidic sandy soil as the bolete, so they confirm the right type of forest, even though they do not promise you a mushroom.

Will I find the netted oak cep in October?

The chances are slim. Of the 223 Ukrainian records of Boletus reticulatus in GBIF, 70.3% fall in June and July, and only 4.5% in October. It is a mushroom of late May, June and July, so in autumn in an oak wood count rather on the classic porcini.

Can you pick the bronze bolete?

Not in Ukraine. The bronze bolete (Boletus aereus) is listed in the Red Book of Ukraine, third edition, 2009, and there it must be left alone. If you meet a dark, almost black bolete in an oak or beech wood, photograph it and leave it to grow.

How do you tell porcini from the bay bolete quickly in the forest?

The surest way is the cut: in porcini the flesh stays white, in the bay bolete it turns blue. Context helps too: in an old conifer forest with thick moss the bay bolete turns up more often. More detail in the comparison of the two.

Porcini by forest type

“I went into the pine forest and filled a basket with porcini” and “I went into the oak wood and filled a basket with porcini” mean two different things. The forest does not just change the mushroom's mood, it often changes the mushroom itself.

Under spruce and birch you will find the same porcini, only dressed differently. Under pine and under oak you are already dealing with other, separate species. So one and the same basket can be filled with several closely related but unlike boletes.

Everything essential is in one table below, and after it come three things people rarely talk about, although they are exactly what decides whether there will be a mushroom at all: the soil, the age of the stand, and the plants under your feet.

Table: who grows under which tree

|---|---|---|---|---|

| Pine | July–October | dark, chestnut-red or wine-brown, glossy in wet weather | massive, with a faint reddish-brown tint, netting only at the top | dry sandy pine forests of middle age, with wavy hair-grass and lichens |

The shortest way to read this table is this: a dark cap and a massive stem mean the pine bolete, a pale honey cap means the birch porcini, and netting running right down to the base of the stem gives away the oak cep.

One mushroom or several, to be precise

It is easy to get muddled here, because in the basket they are all “porcini”. From the point of view of science, though, the picture is not uniform.

The birch porcini is the very same Boletus edulis, and its old separate name Boletus betulicola is now regarded as a synonym. The spruce one, the “classic” porcini, is also B. edulis, just in its typical form. So under birch and spruce you have two forms of a single species.

The pine bolete (Boletus pinophilus) and the netted oak cep (Boletus reticulatus, also known as B. aestivalis), however, are recognised separate species and not forms.

So the honest way to put it is this: some of the “porcini” are forms of one species, and some are species in their own right. And the simplest way to work out which one is in front of you is to look not at the mushroom but around it. The forest tells you more precisely than the shade of the cap. We put together the overall portrait of the whole family in the article porcini, the king of Europe's forests.

The soil matters more than the species of tree

Here is the observation that saves the most time: two neighbouring oak woods can behave completely differently, and the oaks are not the reason.

Porcini leans towards acidic, well-drained, sandy soils. In a study of productive oak stands where the bolete fruited abundantly, soil acidity was pH 4.6, that is, distinctly acidic ground.

The opposite case is limestone soils. The Polish field guide grzyby.pl states outright that porcini avoids them, and on ground like that you meet the brightly coloured boletes instead, mushrooms with vivid pores and a different character altogether.

What this means in practice:

Dry sandy ground that lets water through quickly is more promising than heavy clay.
If a forest keeps giving you brightly coloured boletes with reddish pores and no porcini, the reason may be the soil itself, and walking in circles there is pointless.
Two stands that look alike can differ in acidity alone, and that is exactly what decides the matter.

Stand age: an old pine wood belongs to the bay bolete

The second clue, the one almost nobody mentions, is the age of the forest. Porcini chooses stands of middle age. In older conifer stands it retreats, and its place is taken by the bay bolete.

That is exactly how the Polish Wikipedia describes it in the section on the ecology of porcini: the mushroom prefers stands of the middle age class, and in older conifer stands it yields to the bay bolete.

For you this means something simple. Walk into a tall old pine forest, where the pines have sparse crowns and the needle layer is thick, and set your expectations on the bay bolete rather than on porcini. Walk into a pine stand of middle age, where the trees are not giants yet and the litter is thinner, and the chances of porcini are higher.

It is worth knowing the difference between these two with confidence, because at the cut it is obvious: in porcini the flesh stays white, in the bay bolete it turns blue. For a detailed comparison see the page porcini vs bay bolete.

Signs on the ground

Once you are in a pine forest, there are clues under your feet that make an experienced picker slow down.

For the pine bolete grzyby.pl names two of them: wavy hair-grass (Avenella flexuosa, Deschampsia flexuosa in older sources), that fine grass with drooping stems, and lichens of the genus Cladonia, the pale little bushes and “sticks” on the sand.

Both plants like the same thing the bolete does: poor, acidic, sandy soil. They do not promise you a mushroom, they confirm that you are in the right type of forest.

One more observation, which we take not from the sources but from our own pages on the Xerocomus boletes: thick cushions of moss more often give up the bay bolete than porcini. So in a carpet of moss under old pines, do not be surprised if no porcini turns up at all.

Oak and hornbeam: in October the timetable here is different

If you are reading this in October and planning to go for porcini in an oak wood, here is the main thing to know: the netted oak cep is a mushroom of May, June and July, not of autumn.

The Ukrainian data confirm this clearly. Of the 223 Ukrainian records of Boletus reticulatus in GBIF, 70.3% fall in June and July, and only 4.5% in October. So in autumn an oak wood may give up the classic porcini, but counting on the netted one here is unwise.

Heads up: Ukraine's Red Book. If you come across a dark, almost black bolete of a deep chestnut tone in an oak or beech wood, it is most likely the bronze bolete (Boletus aereus). In Ukraine it is listed in the Red Book (third edition, 2009), so there it is protected and has to be left alone. Photograph it and let it grow. In October such a meeting is unlikely: of the 23 Ukrainian records in GBIF, 12 fall in July and only 5 in October.

And one last thing, independent of the type of forest. Under any tree at all you may run into the bitter bolete, a lookalike with a pinkish underside to the cap and dark netting on the stem. It is not poisonous, but it can ruin an entire dish, so check the sponge before you put a mushroom in the basket. A side-by-side of the field marks is on the page porcini vs bitter bolete, and for the summer cep separately on oak cep vs bitter bolete.

Sources

Borowik szlachetny in the Polish Wikipedia, the section on ecology: the age of stands and displacement by the bay bolete.
grzyby.pl, the Polish mushroom field guide: limestone soils and the indicator plants of pine forests.
A paper on the soils of productive oak stands in the journal Microorganisms (2025, vol. 13, no. 9, article 2196): acidity pH 4.6.
Boletus reticulatus in GBIF, Ukrainian records by month.
Boletus aereus in GBIF, Ukrainian records by month.
The Red Book of Ukraine, third edition (2009).